Handheld portable devices, such as smart phones, lap tops, and tablets, have an exterior part such as an enclosure that is commonly made of plastic or metal. Ceramic materials with high strength, chemical stability, and wear resistance are also used as the materials for forming the exterior parts. The ceramic exterior parts are conventionally formed by methods such as dry pressing, slip casting, and hot injection molding.
Tape casting, which is a technique used to prepare thin films, is adopted for casting ceramic materials to make micron sized electronic parts such as ceramic sensors, piezoelectric members, capacitors, and microwave dielectric components. However, the tape casting has not been used in the forming of the exterior part of the portable device.